My Crazy Neighbour

[Shewhomustgowithoutname]

This has been something that is very irritating. More than that I find these people so strange that it gets a bit scary at times. I really don't like strange.
They watch every move. They have commented on various relatives and legitimate callers to my house. They have commented on visitors' cars and gifts brought by visitors i.e. bunch of flowers. They comment on having seen my relatives out and about in the town. They said about people arriving at strange hours (they work shifts). They were caught one night out in my garden trying to interfere with one of those movement lights.
I have found all this nosiness intrusive and I decided a while back just to go in and out my house without looking at anyone.
They have an outbuilding which is on the dividing line between houses and they cant access certain parts without coming onto my land/garden. They have taken to hosing at the building roof from their garden. My house is covered in water at time. This has severely rusted the movement light on the rear wall of the house. The same light installed at the same time on another area is not rusted at all. I think one is rusted because of all the water sprayed on it. I am also concerned about water ingress to the electrics.
If they acted like civilised human beings they could come to the door and speak to me about accessing their outbuilding from my side I would have given permission. Having done all these things I will not be giving any permissions.
I don't feel safe with such crazy acting folks next door. I am a single parent. I don't want the kids or me hosed down either..
Any suggestions what I should do

[Siwdmae]

Put up fencing so they can't get onto your land. Ensure movement lights aren't pointing at their property because I got really pissed off at the neighbour's searchlight type light being on constantly.

Ignore the neighbours, don't engage in small talk, leave the house and re-enter eyes down.

[Shewhomustgowithoutname]

There is fencing which is joint fencing, been there since the houses were built decades ago. They also have high trees about 40 feet in height. They are not coming on my garden they are hosing from their garden.
I have spent a lot on security to feel safe in my own home. As a result of the way these neighbours carry on I do not speak to them. I go straight out of the garden to the road without looking at anything on anyone.
They are pretty poor folks they could do nothing when there were hooligans here but they hose at the single parent's house.
They are totally weird